1. Field of the Invention
The present invention relates to the detection of the presence of blood pooling or blood flow within the body and within the head, and more specifically, it relates to the diagnosis of stroke.
2. Description of Related Art
The are two forms of stroke: hemorrhagic and ischemic. Hemorrhagic stroke is caused by internal bleeding within the brain. Ischemic stroke is caused by blockage of a blood vessel that feeds the brain or a region of the brain. A stroke attack can occur suddenly and with little or no warning, and can result in severe physical impairment or death. Due to the rapid timescale for potentially severe or fatal damage to the brain these must be treated as rapidly as possible. Surgical intervention can be used to treat hemorrhagic stroke. An anti-clotting agent can be used to treat ischemic stroke. Unfortunately applying an anticlotting agent in the case of hemorrhagic stroke can cause fatal internal bleeding within the brain. At present, there is no non-invasive way to check patients for, and to differentiate between hemorrhagic and ischemic stroke other than computed tomography (CT) and magnetic resonance imaging (MRI).
The cost of computed tomography and magnetic resonance imaging is high. A typical head scan is about $500-$800, and can cost much more if the patient must be sedated or closely monitored during the scan. In many cases, several scans of a single patient are necessary to monitor the development of his/her condition.
The total time required for a scan is about 15 minutes using a helical scan device (faster than the standard CT scanners). If the scanner is physically located right in the emergency room, this time can go down to 5-10 minutes. However, the actual time to diagnose a brain hemorrhage (or other problem) is usually limited by patient transportation, preparation and the need to have a radiologist read the scan. If the scan must be sent out of the emergency room for reading, the overall time can be between 30 minutes and 3 hours.
It is an object of the present invention to provide a microwave hemorrhagic stroke detector that is a low cost, non-invasive, portable device for screening patients for the presence, approximate location, approximate size and rate of internal bleeding within the brain.
It is another object of the present invention to provide a microwave blood flow detector.
Still another object of the invention is to use microbubbles as a contrast agent for microwave imaging of blood flow and hemorrhage.
The microwave hemorrhagic stroke detector can be used at the scene of the injury or stroke incident by the paramedic or first responder in a properly equipped ambulance, in the emergency room (ER), in local clinics and in hospital intensive care units (ICU) and operating rooms (OR). It allows rapid testing of patients prior to CT or MRI scanning, eliminating unnecessary scans, or can replace the use of CT for examining some patients. It has the potential for saving many lives and reducing long term damage to stroke and head injury victims by reducing the time of diagnosis. It also facilitates and reduces the cost of repeated scans to monitor the size and rate of growth of a blood pool within the head. It can greatly reduce the medical costs associated with testing and treating stroke victims, as well as reducing the costs of patient rehabilitation and convalescence by reducing the morbidity resulting from current treatment time delays.
The Microwave Hemorrhagic Stroke Detector is especially beneficial in terms of both cost and time of diagnosis because it can be used for patient screening at the scene of a stroke or in emergency medical centers, providing immediate determination of the nature of the stroke and allowing appropriate, rapid treatment, e.g., surgical intervention or anti clotting drug to be administered.